Question

1 multiple choice 1 point
one property of a gas is that its molecules spread out to fill their container. which of the following best illustrates this property of gases?
a teachers perfume can be detected at the back of the classroom.
rain puddles evaporate more quickly when the sun comes out.
water is produced when hydrogen gas is burned in oxygen gas.
liquid oxygen is denser than gaseous oxygen.
clear my selection
2 multiple choice 3 points
which statement correctly describes the flow of energy through this pyramid?
energy pyramid
tertiary consumers
secondary consumers
primary consumers
producers
all of the energy from the lower levels is available to the top level.
the producer level directly provides energy for all of the other levels.
the highest amount of energy is transferred between levels that contain consumers.
energy is directly transferred from the primary consumers to the secondary consumers.
clear my selection

Explanation:

1. The property of gas molecules spreading out to fill their container is diffusion. A teacher's perfume being detected at the back of the classroom is an example of gas - molecule diffusion. Rain puddles evaporating is a phase - change process, hydrogen and oxygen reacting is a chemical reaction, and comparing liquid and gaseous oxygen densities is about density differences, not gas - filling behavior.
2. In an energy pyramid, producers are at the base and they capture energy from the sun and convert it into chemical energy. This energy is then passed on to primary consumers, secondary consumers, and tertiary consumers. The producer level directly provides energy for all of the other levels. Energy transfer is not 100% efficient, and not all energy from lower levels reaches the top level. The highest amount of energy transfer occurs between producers and primary consumers, and energy transfer between consumer levels is also not the highest.

Answer:

1. A. A teacher's perfume can be detected at the back of the classroom.
2. B. The producer level directly provides energy for all of the other levels.